1. Field of the Invention
The present invention relates to an image forming apparatus for forming images on cut sheets, a sheet humidifier for supplying moisture to cut sheets and a binding system including them.
2. Description of the Related Art
Electrophotographic image formation is generally carried out by transporting cut sheets having toner electrostatically absorbed thereon through a fuser to fuse the toner on to the sheets.
As shown in FIG. 1, however, the fusing of toner with a fuser results in the loss of a considerable amount of moisture included in cut sheets of paper, which reduces the sheet dimensions from initial values. Although the sheet dimensions are recovered because the sheets absorb moisture again as time passes, the fluctuation of dimensions results in various problems. For example, when dry sheets are collected and bound, the glued portion on the back of the book is fixed in a shrunk state. Although each sheet returns to the initial dimensions as a result of subsequent absorption of moisture, "wavy" distortions remain on each sheet because it is constrained by glue in the region of the back. Specifically, as shown in FIG. 2, a book can become wavy as time passes even if it has been beautifully produced.
Further, when a cut sheet is extremely dry before an image is formed, the quality of the image formed thereon can be adversely affected.
The present invention has been conceived taking the above-described situation into consideration, and it is an object of the invention to provide an image forming apparatus, a sheet humidifier and a binding system in which cut sheets can be humidified by force.